Grinding mill

ABSTRACT

D R A W I N G A GRINDING MILL APPARATUS PARTICULARLY SUITED FOR GRINDING SMALL LABORATORY SAMPLES AND THE LIKE. THE DISCLOSED EMBODIMENT INCLUDES A BASE SUPPORT AND MOTOR HOUSING WITH A GRINDING CHAMBER FORMING ASSEMBLY REMOVABLY MOUNTED THEREON. THE GRINDING CHAMBER ASSEMBLY IN COMPRISED OF TWO SEPARABLE SECTIONS EACH DEFINING APPROXIMATELY HALF OF THE CHAMBER. EACH SECTION HAS AN INTERNAL SPACE FOR PERMITTING A HEAT EXCHANGE FLUID TO BE CIRCULATED THERETHROUGH. ADDITIONALLY, A GRINDING BLAME ASSEMBLY IS REMOVABLY MOUNTED IN ONE OF THE SECTIONS.

E. M. KLoPP GRINDING MILL Sept. 20, 1971 5 Sheets-Sheet 1 Filed Feb. 26,1970 INVENTOR. EDWARD M. KLOPP ATTORNEYS Sept. 20, 1971 Filed Feb. 26.1970 E. M. KLOPP GRINDING MILL 5 Sheets-Sheet 2 'INVENTOR. EDWARD M.KLOPP ATTORNEYS.

Sept. 20, 1971 KLQPP 3,606,178

GRINDING MILL Filed Feb. 26, 1970 3 Sheets-Sheet 5 INVENTOR. EDWARD M.KLOPP BY WWW ATTORNEYS.

United States Patent 3,606,178 GRINDING MILL Edward M. Klopp, Medina,Ohio, assignor to The Chemical Rubber Company, Cleveland, Ohio FiledFeb. 26, 1970, Ser. No. 14,559 Int. Cl. B02c 18/12, 23/00 US. Cl. 241-656 Claims ABSTRACT OF THE DISCLOSURE A grinding mill apparatusparticularly suited for grinding small laboratory samples and the like.The disclosed embodiment includes a base support and motor housing witha grinding chamber forming assembly removably mounted thereon. Thegrinding chamber assembly is comprised of two separable sections eachdefining approximately half of the chamber. 'Each section has aninternal space for permitting a heat exchange fluid to be circulatedtherethrough. Additionally, a grinding blade assembly is removablymounted in one of the sections.

The present invention is directed toward the grinding mill art and, moreparticularly, to an improved rotary blade type mill.

The invention is particularly suited for small mills for use inlaboratories for grinding small quantities for samples and the like, andwill be described with particular reference thereto; however, it will beappreciated that the invention is capable of broader application andcould be used for mills of substantially any size and use.

Grinding mills suitable for laboratory use must be capable of rapidlyand efficiently griding small samples of a wide range of materialshaving substantially different properties. Also, it is mandatory that atleast the grinding chamber portion of the mills be arranged for quickdisassembly for cleaning, sterilization, etc. In addition to theserequirements, it is highly desirable that there be provision forselectively heating or cooling the chamber during a grinding operation.

The three above noted factors are somewhat mutually incompatible from adesign standpoint. The present invention however, provides a grindingmill which meets the requirements simply and effectively.

In accordance with the invention there is provided an improved grindingmill including first and second grinding chamber forming sections eachcomprised of an outer housing member having a continuous side wall, aclosed lower end and an open upper end. Generally cup shaped linermembers are positioned within each housing member and in combinationtherewith define separate sealed annular chambers. Connecting means areprovided for releasably connecting the two grinding chamber formingassemblies with their open ends in face-to-face engagement whereby theirliners cooperate to form a closed grinding chamber. A readily releasablerotary grinding knife and bearing assembly extends through the closedend wall of one of the housings and into grinding chamber. Additionally,there is a base assembly having a motor with a vertically extendingoutput shaft and means carried by the base assembly for positioning thegrinding chamber assembly thereon with means for pro viding a releasabledrive connection between the grinding knife and the motor shaft.

Accordingly, a primary object of the invention is the provision of agrinding mill which can be readily disassembled and which is capable ofgrinding a variety of diiferent materials.

Another object of the invention is the provision of a rotary grindingmill of the type described wherein a heat exchange fluid can becirculated about the grinding chamber.

A further object is the provision of a grinding mill particularly suitedfor use in laboratories and in which the grinding chamber is comprisedof two substantially identical manually releasable sections that can becompletely disassembled for cleaning etc.

Yet another object is the provision of a mill of the type describedwhich is extremely rugged and relatively simple in construction.

These and other objects and advantages will become apparent from thefollowing description when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a pictorial elevation of a grinding mill formed in accordancewith the preferred embodiment of the invention;

FIG. 2 is a vertical cross-sectional view taken through the mill of FIG.1;

FIG. 3 is an enlarged cross-sectional view through the cutter assembly;

FIG. 4 is a cross-sectional view through the grinding chamber assemblyshowing in detail the connecting and sealing arrangement between thegrinding chamber forming members; and,

FIG. 5 is a view taken on line 5-5 of FIG. 2.

Referring more particularly to FIGS. 1 and 2, the overall mill is shownas comprised of a motor and base assembly 10 and a grinding chamberforming assembly 12. Preferably the grinding chamber forming assembly isreleasably mounted on the assembly 10.

The base and motor assembly 10 could have a variety of designs andconfigurations but, in the preferred embodiment, includes a housing 14formed, for example, from cast aluminum. The housing 14 is open at itslower end 16 and is provided with a relatively heavy, inwardly extendingmotor mounting flange 18 at its upper end. The inner corners of thehousing 14 are provided with heavier portions which serve to strengthenthe housing and provide means for attaching the base plate.

As shown, the open lower end 16 of the housing 14 is closed by a baseplate member 22 which is formed, for example, from sheet aluminum. Toassure circulation of cooling air through the motor chamber 26, the baseplate member 22 is provided with a series of openings 24. Similarly, thehousing 14 is provided with openings 27. A circulation of air is due tothe presence of a fan, built into the motor, which pulls air through theopening 27, through and around the motor, and discharges it through theholes in the base plate.

Resilient rubber pads or feet 28 are positioned at each lower corner ofthe housing and releasably connected thereto by machine screws 30 whichare received in threaded openings formed in the portions 20. As can beseen from FIG. 2, the base plate is fastened to the housing by the samemachine screws that hold the rubber feet.

Positioned within the motor chamber 26 is a conventional, high speedelectric motor 32. The motor is supported from the flange 18 by fourmachine screws 34 which extend downwardly through openings in flange 18and into threaded alignment bosses on the casing of the motor '32. Themotor could be of many types but is preferably capable of approximately20,000 rpm. As shown, the motor is mounted so that its output shaft 36extends vertically upwardly through opening 38 and into releasableengagement with the cutter assembly which will subsequently bedescribed.

Any of a variety of types of controls could be provided for the mill. Inthe embodiment under consideration, the controls include an adjustableelectrically driven timer 39 which mounted on the inclined face 40 ofthe housing 14. The timer 39 is provided with a knob 42 used to 3 adjustthe timing mechanism for any predetermined period of time. Also, thetimer is preferably of the type which permits it to be set for continousuntimed operation of the motor. In addition to the timer, the device isprovided with a pilot light 44 and a breaker for overload protection.

The apparatus thus far described is relatively conventional and couldvary substantially from that shown. Of special importance to theinvention however, is the arrangement of the grinding chamber assembly12. As will hereafter become apparent, the assembly 12 could have manydifferent constructions but, in the preferred embodiment, includes afirst chamber forming assembly 44 and a cooperating second chamberforming assembly 46 which together define a closed and sealed grindingchamber 48.

The assembly 44 includes an outer housing member 50 which has acontinuous outer side wall 52 which is desirably shaped so as to form acontinuation of the side wall of the base housing 14. The housing 50 ispreferably formed from cast aluminum and is releasably mounted andpositioned on the upper edge of the base 14 by pin members 54 whichextend vertically upward from the housing 14. As shown, the pin members54 are received in openings 56 formed in the lower edge of the wall 52.This properly positions the housing 50 relative to the housing 14 whilepermitting it to be readily removed for cleaning, emptying, etc.

An internal inwardly extending central flange or Wall 58 is integrallyformed with the wall 52. Flange 58 carries the removable cuttingassembly 60 in a manner subsequently to be described. Adjacent the upperend of the housing 50 there is a second inwardly extending flangeportion 62 which extends about the entire periphery of the wall 52. Theflange portion 62 terminates in a cylindrical opening 64.

The actual grinding chamber is defined by a generally cup shaped linermember 68 which is positioned within the opening 64. Preferably, themember 68 is formed from stainless steel or the like so that it has goodcorrosion resistance and can be used for grinding a variety ofmaterials. As best shown in FIG. 4 the upper edge of the cup shapedliner member 68 is provided with a radially outwardly extending flange70. The flange 70 rests on the upper surface of the housing flange 62.Preferably, sealing means are arranged to provide a fluid tight sealbetween the flange 70 and the housing flange angle 62. In the embodimentunder consideration, the sealing means includes an O-ring 72 which isreleasably positioned in a groove 74 that extends circumferentiallyabout the opening 64.

Referring again to FIG. 2, it will be noted that with the member 68 inposition, the wall 52 cooperates therewith to form a generally annularshaped closed chamber 76 about the member 68. This permits a heating orcooling fluid to be circulated about the member 68 so that grinding canbe accomplished at any desired temperature. In the embodiment shown,heat exchange fluid inlets and outlets extend through the wall 52. Theinlet and outlets are formed by a pair of connectors 78 which arethreadably received in the wall 52. The connectors 78 are theconventional type used with flexible tubing. Note that a short sectionof tubing 80 is shown received on the outer end of the connector 78.

The upper portion of the grinding chamber is formed by assembly 46 whichis releasably connected to assembly 44. The grinding chamber formingassembly 46 is broadly similar to assembly 44. As best shown in FIGS. 1and 4, the assembly 46 comprises a first outer housing member 82 whichis preferably an aluminum casting of generally rectangular cup shapedconfiguration. As can be seen, the housing member 82 has a downwardlyextending wall 84 which is shaped so as to form a continuation of thewall 52 of housing member 50. Positioned within the open lower end ofthe housing member 82 is a generally cup shaped grinding chamber formingmember 88. Member 88 is preferably drawn fIQm Stainless steel.

4 As shown in FIG. 4, the cup shaped liner member 88 has a radiallyoutwardly extending flange 90 which serves to position it within thehousing member 84. Additionally, the upper wall 92 of housing member 84'is provided with a central downwardly extending boss portion 94 whichengages the center of the end wall member 88.

The member 88 is removably received in the housing 84 by an annular ringmember 9'6 which is press fitted within the housing 82. As shown, member96 is received in a recess or shouldered portion 98 formed about theinner periphery of wall 84. The liner .88 is, in turn, press fit withinmember 96. Positioned between the lip 90 and the member 96 is aresilient gasket 100 which provides a fluid tight chamber 102 about theliner 88. The chamber can be seen in FIG. 2 and, like chamber 76, isprovided with means for supplying heating or cooling fluid to maintain adesired temperature in upper portion of the grinding chamber 48. Themeans used for supplying fluid to the chamber 102 comprise a pair oftube fittings 104 which are received in threaded openings formed throughthe walls of housing 82.

The grinding chamber forming assemblies 44 and 46 are arranged so thatthey can be readily released to permit access to the interior of thegrinding chamber 48. These releasable means can take many forms but, inthe subject embodiment, comprise cooperating engageable lip portionscarried on each of the assemblies. As best shown in FIG. 5, on theassembly 44 there is connected an annular lip forming member which isarranged to extend inwardly a short distance beyond the innermost edgeof the top surface of wall 52. This member is cut out at diagonallyopposite positions and the upper annular ring 96 is adapted toreleasably engage under the member 110 and has a pair of diagonallyopposite outwardly extending lip portions 112. The lip portions arepositioned so that they can pass through the openings in member 110 and,since the lips include an inclined ram portion when rotated a shortangular distance clockwise, engage under lip 110 to lock assemblies 44and 46 tightly together.

As can be appreciated, in the apparatus thus far described, thearrangement of the grinding chamber assemblies 44 and 46 permits them tobe removed as a unit from the motor assembly 10 and, additionally,permits each of the individual assemblies 44, 46 to be disassembled forcleaning, autoclaving, etc.

In line with the ability of the assemblies 44 and 46 to be disassembled,the cutter assembly 60 is likewise arranged so that it can be easilymoved from the assembly 44. Referring in particular to FIG. 3, it willbe noted that a locking bushing member is joined, such as by silversoldering, to the lower end surface of the cup shaped member 68. Thebushing member 120 is adapted to be closely received in the centralopening in the circumferential flange 58. An O-ring seal 122 is receivedin an annular groove 124 formed about the top surface of flange 58'.This provides a tight seal for the annular chamber 76. The lockingbushing 12!) is removably connected to the flange 58 by a nut 126.

Removably seated within the locking bushing. 12!) is a bearing sleevemember 128 which has an outwardly extending flange 130 at its upper end.Flange 130 rests against the upper surface of the locking bushing 120.The bearing sleeve 128 is resiliently held in position by a nut 130which bears against a resilient cup washer 132 which is positioned asshown, between the lower surface of flange 58 and the upper surface ofnut 130. A sleeve hearing 134 is carried within the bearing sleeve 128and includes a flange portion 136 which cooperates with a recess formedwithin the bearing sleeve.

The cutter drive shaft 138 extends vertically through the bearing 136and has a threaded upper end portion 140 which receives the cutter blade142. A thrust washer 144 is positioned between the lower surface ofblade 142 and the upper surface of the bearing sleeve 128. An acorn nut146 locks the blade in position. Although not shown, the opening throughthe blade is threaded so that it can be threaded onto the portion 140 ofthe drive shaft. The drive shaft is enlarged at its lower end 148 toprovide a shoulder 150 which has a suitable Washer or washers 152positioned thereon to engage the lower end of the bearing 134.

The drive shaft 138 is, of course, releasably connected to thevertically extending shaft 36' of motor 3-2. Many types of releasableconnections could be used; however, in the subject embodiment the lowerend 148 of the drive shaft 138 is provided with an octagonal recess(made by superimposing two squares 45 out of phase). The motor shaft 36is, as best seen in FIG. 2, provided with a flexible coupling the upperend of which includes a square steel drive pin which slidably engageswith the recessed portion of 148.

As can be appreciated from the aforegoing description, the inventionpermits the grinding chamber portion of the assembly to be readilyremoved from the base assembly 10. The construction of the cutterassembly and the individual chamber forming assemblies 44 and 46 is suchas that they can be readily disassembled for cleaning etc. Additionally,the arrangement is such that filling and emptying of the chamber iseasily accomplished and heating and/or cooling can also be carried outwith a minimum of efiort.

The invention has been described in great detail sufficient to enableone of ordinary skill in the grinding art to make and use the same.Obviously, modifications and alterations of the preferred embodimentwill occur to others upon a reading and understanding of thespecification and it is my intention to include all such modificationsand alterations as part of my invention insofar as they come within thescope of the appended claims.

Having thus described my invention, I claim:

1. An improved grinding mill comprising:

a first grinding chamber forming assembly including a first outerhousing member having a continuous side wall, a closed lower end and anopen upper end; a first generally cup shaped liner member positionedwithin said first housing member and defining a first sealed annularchamber in combination therewith;

a second grinding chamber forming assembly comprising a second outerhousing member having a continuous side wall, a closed upper end and anopen 6 lower end; a second generally cup shaped liner member positionedwithin said second outer housing member and defining a second sealedannular chamber in combination therewith;

a rotary grinding knife and bearing assembly extending through theclosed end wall of said first housing and into said first liner, meansfor releasably retaining said grinding knife and bearing assemblytherein; and,

connecting means for releasably connecting said first and secondgrinding chamber forming assemblies with their open ends in face-to-faceengagement whereby said liners cooperate to form a closed grindingchamber.

2. The invention as defined in claim 1 including means for supplyingheat exchange fluid to said first and second annular chambers.

3. The invention as defined in claim 1 including a base assemblyincluding a motor having a vertically extending shaft.

4. The invention as defined in claim 1 wherein said connecting meanscomprise rotatably engagea-ble portions carried on said first and secondhousing members.

5. The invention as defined in claim =1 including a base assembly havinga motor with a vertically extending out put shaft, means carried by saidbase assembly for positioning said first grinding chamber assemblythereon; and, releasable means for drivingly connecting said outputshaft to said rotary grinding knife.

6. The invention as defined in claim 1 wherein said first and secondliner members are generally cylindrical and of the same diameter, andwherein said liner members each have lips which extend radially andengage when said first and second grinding chamber assemblies areconnected.

References Cited UNITED STATES PATENTS 3,243,128 3/1966 Tight 241-THERON E. CONDON, Primary Examiner R. L. SPRUILL, Assistant Examiner US.Cl. X.R. 24l185

